不同胶粘面积钢板加气混凝土砌块粘结性能试验

Bonding performance of steel plate aerated concrete blocks with different adhesive areas

针对新型地下粮仓采用钢板作为防水层、环氧结构胶粘结钢板与加气混凝土砌块作为防潮层的构造做法,分析在粮食水平侧压力及竖向摩擦力作用下该构造层的安全性与可靠性,设计3种胶粘面积分别为A、0.8A、0.5A的试件(A为单块加气混凝土砌块与钢板的接触面积),分别对其进行竖向单向加载与水平-竖向双向加载,分析3种胶粘面积及2种受力状态对钢板加气混凝土砌块构造层的荷载-位移、承载能力、粘结强度及破坏形态的影响。研究结果表明:水平荷载即仓内储粮产生的水平侧压力对界面粘结性能是有利的;试件在水平-竖向双向加载时更有利于界面的稳定;竖向单向加载作用下胶粘面积为0.5A时的理论最大储粮高度最小,且大于实际储粮高度,说明在地下粮仓设计中,当环氧结构胶粘结面积超过加气混凝土砌块与钢板接触面积的50%时,能够满足储粮荷载作用下的承载能力及粘结强度要求。研究成果可为新型地下粮仓防水防潮构造层的安全性与可靠性提供参考依据。

A reinforced concrete subsoil granary has been the promising type in agricultural production in recent years.Among them,a steel plate is used as the waterproof layer,which is connected to the reinforced concrete silo wall by welded bolts on the contact side of the steel plate and the reinforced concrete silo wall.The moisture-proof layer is taken as the aerated concrete blocks using epoxy structural adhesive.Specially,the aerated concrete block is bonded to the steel plate,thus forming a structural layer of epoxy structural adhesive bonding the steel plate and aerated concrete block.This study aims to evaluate the safety and reliability of this structural layer under the horizontal lateral pressure and friction of grain.The results are as follows:1)Once the adhesive area was the same,there was the increase in the deformation,ultimate bearing capacity and bond strength at the interface of steel plate aerated concrete block under horizontal-vertical bidirectional loading,compared with the vertical unidirectional loading.The better bonding performance was then achieved under the horizontal lateral pressure that generated by the grain storage in the silo;2)The damage pattern of vertical unidirectional loading was obtained,where the aerated concrete blocks were peeled off from the epoxy structural adhesive;In horizontal-vertical bidirectional loading,a penetrating crack was formed in the aerated concrete blocks,and then the whole block moved downward under the horizontal load,but without peeling off.A comparison was made on the damage patterns of vertical unidirectional loading and horizontal-vertical bidirectional loading.Therefore,it was beneficial to the stabilization of the interface,in the case of aerated concrete blocks under vertical loading while applied horizontal lateral pressure.3)The bond strength was closely related to the friction force on the silo wall,when the adhesive area was A,0.8A,0.5A(A was the contact area between a single aerated concrete block and a steel plate).Once the adhesive area was 0.5A,the smallest height of grain storage was achieved under the vertical unidirectional loading,indicating the larger than the actual height.Therefore,the structural layer with the gluing area of 0.5A was fully met the requirements of the bearing capacity and bonding strength under grain storage loads in the design of underground granaries.4)It was feasible to adopt the construction practice of epoxy structural adhesive bonding steel plates and aerated concrete blocks for underground granaries under the horizontal lateral pressure and vertical friction of grain.5)The bearing capacity and bond strength were fully met the requirements,when the bonding area of epoxy structural adhesive exceeded 50%of the total area of aerated concrete block.Further consideration should be given to the influence of the epoxy structural adhesive thickness and application mode on the displacement,bearing capacity,bond strength and damage pattern of the structural layer.The findings can provide a strong reference for the safety and reliability of the waterproof and moisture-proof structural layer in the new underground granary.